What we actually got was a surreal mixture of boogie woogie and punk, with Benjamin B. dancing around the stage in the style of Buddy Holly. Apparently he describes his sound as 'if Otis Redding joined a punk band'.
The show was further enlivened when BB called an audience member called Pablo on stage and instructed him to crowd surf around the venue. Then when some security guards (who probably didn't understand much of what was being said) tried to drag Pablo off, BB dived off stage to rescue him. It was quite something. Once he and Pablo were safe again on stage he gave the audience permission to basically do what they wanted to security.
I got most of this exchange on video at the link below, though I can't embed it at the moment.
I'd say BB went a bit far in his comments about security and there may well be repercussions for his set at the festival itself but it was as visceral and spontaneous thing as I've ever seen a star on a stage do.
There is a great NPR interview with him about the origins of his sound and his interest in protest. I will definitely be lookin to find out more about him and his music when I get home.